Charged particle beam device and pattern measurement device

Abstract

The present invention provides a charged particle beam device capable of predicting the three-dimensional structure of a sample, without affecting the charge of the sample. The present invention provides a charged particle beam device characterized in that a first distance between the peak and the bottom of a first signal waveform obtained on the basis of irradiation with a charged particle beam having a first landing energy, and a second distance between the peak and the bottom of a second signal waveform obtained on the basis of irradiation with a charged particle beam having a second landing energy different from the first landing energy are obtained, and the distance between the peak and the bottom at a landing energy (zero, for instance) different from the first and second landing energies is obtained on the basis of the extrapolation of the first distance and the second distance.

The invention claimed is: 
     
       1. A charged particle beam device which includes scanning deflector for a scanning with a charged particle beam emitted from a charged particle source, a detector for detecting the charged particle obtained based on the scanning with the charged particle beam with respect to a sample, and a computation device for generating a signal waveform based an on output of the detector and computing a pattern dimension formed on the sample by using the signal waveform,
 wherein the computation device calculates an index value relating to a pattern formed on the sample from at least a first measurement result obtained by the scanning with the charged particle beam having first landing energy and a second measurement result obtained by the scanning with the charged particle beam having second landing energy. 
 
     
     
       2. The charged particle beam device according to  claim 1 ,
 wherein the first measurement result and the second measurement result are dimensional values relating to the pattern and the computation unit calculates an edge dimension value at third landing energy other than the first landing energy and the second landing energy by extrapolation. 
 
     
     
       3. The charged particle beam device according to  claim 2 ,
 wherein the third landing energy is zero. 
 
     
     
       4. The charged particle beam device according to  claim 1 ,
 wherein the first measurement result and the second measurement result are obtained based on a width of a peak of the signal waveform. 
 
     
     
       5. The charged particle beam device according to  claim 4 ,
 wherein the first measurement result and the second measurement result are dimensional values relating to a taper of the pattern. 
 
     
     
       6. The charged particle beam device according to  claim 1 ,
 wherein the computation device estimates a taper angle of the pattern from change in a position of a bottom end of the pattern when scanning is performed with different landing energies. 
 
     
     
       7. The charged particle beam device according to  claim 1 ,
 wherein the computation device displays a taper distance and a round region of the pattern obtained based on extrapolation of the first measurement result and the second measurement result as a three-dimensional structure. 
 
     
     
       8. The charged particle beam device according to  claim 7 ,
 wherein the computation device displays a taper amount and a round amount of a pattern included in an image in a map form on a display device. 
 
     
     
       9. The charged particle beam device according to  claim 7 ,
 wherein the computation device estimates height information of the pattern from a signal amount of the bottom of the pattern and estimates and displays the three-dimensional structure in combination with a taper shape and a round shape of the pattern. 
 
     
     
       10. The charged particle beam device according to  claim 1 ,
 wherein the computation device identifies the pattern or a type of an edge of the pattern based on the index value. 
 
     
     
       11. A charged particle beam device which includes a charged particle source, a deflector for a scanning with a charged particle beam emitted from the charged particle source onto a sample, a detector for detecting electrons emitted from the sample by the scanning with the charged particle beam with respect to the sample, an image memory for storing a signal obtained in the detector, a control device for controlling the deflector, the charged particle beam device comprising:
 a computation device for measuring a dimension of a pattern formed on a sample based on irradiation of the charged particle beam, 
 wherein the computation device obtains a first distance between a peak and a bottom of a first signal waveform obtained based on irradiation with a charged particle beam, having a first landing energy and a second distance between a peak and a bottom of a second signal waveform obtained based on irradiation with a charged particle beam having a second landing energy different from the first landing energy and obtains a distance between the peak and the bottom at a landing energy different from the first and second landing energies based on extrapolation of the first distance and the second distance. 
 
     
     
       12. A pattern measurement device and a program which includes a computation device for generating a signal waveform based on a detection signal obtained by a charged particle beam device and calculating the dimension of a pattern formed on a sample using the signal waveform,
 wherein the computation device calculates an index value relating to the pattern formed on the sample at least from a first measurement result obtained by a scanning with the charged particle beam having first landing energy and a second measurement result obtained by the scanning with the charged particle beam having second landing energy.